Vax-induced antibodies may be less effective against newer COVID variants – Edexlive

The neutralizing antibodies induced by the Pfizer and Moderna Covid-19 vaccines were significantly less effective against the SARS-CoV-2 variants first described in Brazil / Japan and South Africa, the researchers say.

The team used their experience measuring HIV neutralizing antibodies to create similar tests for Covid-19, comparing the effectiveness of antibodies against the original strain versus the newer variants.

“We were able to take advantage of the unique high-speed capability already in place and apply it to SARS-CoV-2,” said researcher Alejandro Balazs of Massachusetts General Hospital in the United States.

“When we tested these new strains against vaccine-induced neutralizing antibodies, we found that the three new strains first described in South Africa were 20 to 40 times more resistant to neutralization, and the two strains described for the first time in Brazil and Japan were five to seven times more resistant than the original SARS-CoV-2 virus, ”Balazs added.

According to the study, published in the journal Cells, neutralizing antibodies work by binding tightly to the virus and preventing it from entering cells, thereby preventing infection.

Like a key in a lock, this binding only occurs when the shape of the antibody and the shape of the virus are perfectly matched to each other, the researcher said.

If the shape of the virus changes where the antibody attaches to it – in this case, in the SARS-CoV-2 spike protein – then the antibody may no longer be able to recognize and neutralize the virus as well. The virus would then be described as resistant to neutralization, they added.

Currently, all approved Covid-19 vaccines work by teaching the body to produce an immune response, including antibodies, against the SARS-CoV-2 spike protein. While the ability of these variants to resist neutralizing antibodies is of concern, this does not mean that the vaccines will not be effective.

“The body has other methods of immune protection besides antibodies,” Balazs said.

“Our findings do not necessarily mean that vaccines will not prevent Covid, only that the antibody part of the immune response may have trouble recognizing some of these newer variants,” Balazs added.